X(Cross) Reference Attributes parameter entitysee %xref-atts;
X(Cross) Reference Elements parameter entitysee %xref-elements;
X - Generated Text/Punctuation Attributes parameter entitysee %x-atts;
X - Generated Text/Punctuation Class Elements parameter entitysee %x.class;
X - Generated Text/Punctuation Elements parameter entitysee %x-elements;
X - Generated Text and Punctuation
XHTML 1.1 Table Inline Style Module parameter entitysee %xhtml-inlstyle-1.mod;
XLinkuse <ext-link>
XLink Link Attributes parameter entitysee %link-atts;
XLink Linking Attributes for Optional Linking parameter entitysee %might-link-atts;
XLink namespacesee Namespaces and MathML
XLink Namespace Declaration parameter entitysee %XLINK.xmlns.attrib;
XML document instance codesee <code>
XML ID/IDREFsee @id
XML Schema Namespace Declaration
xrefsee <ext-link>see <uri>